typedef struct xauth {
unsigned short family;
unsigned short address_length;
char *address;
unsigned short number_length;
char *number;
unsigned short name_length;
char *name;
unsigned short data_length;
char *data;
} Xauth;
char *XauFileName (void); Xauth *XauReadAuth (FILE *auth_file); int XauWriteAuth
(FILE *auth_file, Xauth *auth); Xauth *XauGetAuthByAddr (unsigned short
family, unsigned shortaddress_length, char *address, unsigned shortnumber_length,
char *number);Xauth *XauGetBestAuthByAddr (unsigned short family, unsigned
shortaddress_length, char *address, unsigned shortnumber_length, char *number,
int types_length, char**types, int *type_lengths); int XauLockAuth (char
*file_name, int retries, inttimeout, long dead); int XauUnlockAuth (char
*file_name); int XauDisposeAuth (Xauth *auth); Description
XauFileName generates
the default authorization file name by first checking the XAUTHORITY environment
variable if set, else it returns $HOME/.Xauthority. This name is statically
allocated and should not be freed. XauReadAuth reads the next entry from
auth_file. The entry is not statically allocated and should be freed by
calling XauDisposeAuth.
XuWriteAuth writes an authorization entry to auth_file.
It returns 1 on success, 0 on failure.
XauGetAuthByAddr searches for an
entry which matches the given network address/display number pair. The
entry is not statically allocated and should be freed by calling XauDisposeAuth.
XauGetBestAuthByAddr is similar to XauGetAuthByAddr, except that a list
of acceptable authentication methods is specified. Xau will choose the
file entry which matches the earliest entry in this list (e.g., the most
secure authentication method). The types argument is an array of strings,
one string for each authentication method. types_length specifies how many
elements are in the types array. types_lengths is an array of integers representing
the length of each string.
XauLockAuth does the work necessary to synchronously
update an authorization file. First it makes two file names, one with ``-c''
appended to file_name, the other with ``-l'' appended. If the ``-c'' file already
exists and is more than dead seconds old, XauLockAuth removes it and the
associated ``-l'' file. To prevent possible synchronization troubles with NFS,
a dead value of zero forces the files to be removed. XauLockAuth makes
retries attempts to create and link the file names, pausing timeout seconds
between each attempt. XauLockAuth returns a collection of values depending
on the results:
LOCK_ERROR A system error occurred, either a file_name
which is too long, or an unexpected failure from
a system call. errno may prove useful.
LOCK_TIMEOUTretries attempts failed
LOCK_SUCCESS The lock succeeded.

XauUnlockAuth undoes the work of XauLockAuth by unlinking both the ``-c'' and
``-l'' file names.